CVE-2026-40355

Exploitation

Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.

SSVC decision

• ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.61% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 46.8% of scored records. A rank, not a probability.

NVD base score

7.5 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

NVD analysis status

Modified. NVD last modified this record on 2026-07-14.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-04-28 00:00Z4 MO AGO

Last updated

2026-07-14 12:48Z1 MO AGO

Reserved

2026-04-11

Assigning CNA

mitre

Record state

PUBLISHED

Severity

Medium (CVSS 5.9)

CNA CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Weaknesses

• CWE-476NULL Pointer DereferenceBase

Data version

5.2

Document digest

f542dc1e2d808e675ef507d32197c00da8cef953e105f2c8e6ee9baa3bfe1d25

• web.mit.eduhttps://web.mit.edu/kerberos/advisories/
• cems.funhttps://cems.fun/2026/04/27/krb5-two-unauthenticated-network-vulnerabilities.html
• github.comhttps://github.com/krb5/krb5/commit/2e75f0d9362fb979f5fc92829431a590a130929f
• cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/html/ssa-082556.html
• cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/html/ssa-019113.html